Determination of Cell Viability after Laparoscopic Tissue Stapling in a Porcine Model

Abstract

Surgical stapling devices are often used to secure the distal ureter along with a cuff of bladder during laparoscopic nephroureterectomy. As the viability of cells within the stapled tissue would be important in patients with upper urinary-tract transitional-cell carcinoma, we determined the viability of cells within the lines of various commercially available staplers in a porcine model. Four laparoscopic stapling devices were used: two vascular and two tissue designs (US Surgical, Norwalk, CT, and Ethicon, Cincinnati, OH). The devices were deployed across a portion of the bladder, much as they would be during a nephroureterectomy to create a bladder cuff while excising the distal ureter. The animals were sacrificed 6 weeks later, and the stapled sites were harvested for histopathologic examination by an experienced genitourinary pathologist (PH). Grossly, there were no visible staples at harvest of the stapled bladder and the ureterovesical junction, with a completely healed bladder being seen in all four animals. On histologic examination with hematoxylin and eosin staining, there were distinctly viable cells within the staple lines of the ureterovesical junction and the bladder wall, similar to the unstapled control tissue. There were viable cells in all samples of tissues stapled by either vascular or tissue staplers. Deployment of both vascular and tissue staplers resulted in viable cells within the staple lines at the ureterovesical junction and bladder wall in this porcine model. There is a potential risk of tumor recurrence at the stapled site in patients who have the ureter and bladder cuff secured with these devices during laparoscopic nephroureterectomy for upper-tract transitional-cell carcinoma. Despite this concern, to date, over a period of 13 years, clinical experience has not revealed a single case of tumor recurrence within the stapled cuff of bladder. Careful endoscopic evaluation of the stapled bladder-cuff site after laparoscopic nephroureterectomy should minimize the potential for local tumor recurrence.